Characterization of errors in satellite-based HCHO / NO2 tropospheric column ratios with respect to chemistry, column-to-PBL translation, spatialrepresentation, and retrieval uncertainties

The availability of formaldehyde (HCHO) (a proxy for volatile organic compound reactivity) and nitrogen dioxide (NO2) (a proxy for nitrogen oxides) tropospheric columns from ultraviolet-visible (UV-Vis) satellites has motivated many to use their ratios to gain some insights into the near-surface ozone sensitivity.